[Chromecast] Handle device scale factor correctly

chromecast/browser/test/chromecast_browser_test_helper_default.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chromecast/browser/test/chromecast_browser_test_helper.h"
 
 #include "base/memory/ptr_util.h"
 #include "chromecast/browser/cast_browser_context.h"
 #include "chromecast/browser/cast_browser_process.h"
 #include "chromecast/browser/cast_content_window.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/test_navigation_observer.h"
 
 namespace chromecast {
 namespace shell {
 namespace {
 
 class DefaultHelper : public ChromecastBrowserTestHelper {
  public:
   ~DefaultHelper() override {}
 
   content::WebContents* NavigateToURL(const GURL& url) override {
     window_.reset(new CastContentWindow);
-    gfx::Size initial_size(1280, 720);
 
     web_contents_ = window_->CreateWebContents(
-        initial_size, CastBrowserProcess::GetInstance()->browser_context());
-    window_->CreateWindowTree(initial_size, web_contents_.get());
+        CastBrowserProcess::GetInstance()->browser_context());
+    window_->CreateWindowTree(web_contents_.get());
 
     content::WaitForLoadStop(web_contents_.get());
     content::TestNavigationObserver same_tab_observer(web_contents_.get(), 1);
     content::NavigationController::LoadURLParams params(url);
     params.transition_type = ui::PageTransitionFromInt(
         ui::PAGE_TRANSITION_TYPED | ui::PAGE_TRANSITION_FROM_ADDRESS_BAR);
     web_contents_->GetController().LoadURLWithParams(params);
     same_tab_observer.Wait();
 
     return web_contents_.get();
   }
 
  private:
   std::unique_ptr<CastContentWindow> window_;
   std::unique_ptr<content::WebContents> web_contents_;
 };
 
 }  // namespace
 
 std::unique_ptr<ChromecastBrowserTestHelper>
 ChromecastBrowserTestHelper::Create() {
   return base::WrapUnique(new DefaultHelper());
 }
 
 }  // namespace shell
 }  // namespace chromecast